A Note from the Author: As most of you reading this were likely not indoctrinated by a secret society of female assassins, and therefore are not fluent in flawless Russian, the word "сестра" translates to "sister" in English.

...

     Even as my sister's name pierced the air, my knees turned to jelly and she closed the distance between us, collecting me in her arms. Suddenly, I was four years old again, repeating my sister's name through tears and clutching at her jacket with white-knuckled fingers, terrified that someone would tear us apart.

     "I thought I'd never see you again," I managed between muffled sobs. "How did you escape?"

     "That's a different story for another time, little one. What matters is that we're together," Natasha replied, stroking my hair.

     When Coulson politely cleared his throat, Natasha whispered, "Come now, little sister, we have a job to do. There will be time for tears later."

     I nodded and slowly got to my feet, wiping the tears from my eyes, "Yes, of course. My apologies. That was unprofessional."

     "No need to apologize, Miss Romanoff," Coulson replied with a small smile. "It was quite heartwarming, actually."

     When Natasha rose to her full height, she looked up...and I looked down, both suddenly aware of the five-inch height difference between us.

     My sister smirked, "You've gotten tall. How dare you."

     I snorted, "Don't be jealous. It's not a good look on you."

     Natasha rolled her eyes before turning to Coulson, "They need you on the bridge. They're starting the face-trace."

     "See you there."

     Gesturing for me and Rogers to follow, my sister said, "It was quite the buzz around here, finding you in the ice. I thought Coulson was gonna swoon. Did he ask you to sign his Captain America trading cards yet?"

     Steve arched an eyebrow and smirked, "Trading cards?"

     "They're vintage. He's very proud."

     As we headed toward the bridge, Steve spotted the resident physicist – who looked rather out of place amongst the hustle and bustle – and called, "Dr. Banner?"

     "Yeah, hi," he replied absentmindedly before shaking Steve's hand. "They told me you would be coming."

     "Word is, you can find the cube."

     "Is that the only word on me?"

     "Only word I care about."

     Banner nodded thoughtfully, then gestured to the tarmac, "It must be strange for you, all of this."

     "Well, this is actually kind of familiar."

     Banner smirked, then turned toward me, "Hi. I don't believe we've met."

     "Anastasia Romanoff. Pleasure."

     "Romanoff? As in—"

     "The very same. Natasha is my older sister. I take it you two have already met."

     "That's one way to put it," he chuckled.

     "You may all want to step inside in a minute," Natasha interjected. "It's going to get a little hard to breathe."

     "Flight crew, secure the deck," an agent said over the public-announcement system.

     As the aircraft carrier started to vibrate, Steve asked, "Is this a submarine?"

     "Really?" Banner scoffed as he faced Natasha. "They want me in a submerged, pressurized, metal container?"

     Natasha merely shrugged in response as the aircraft carrier rose from the water to uncover four massive turbine engines, revealing that this was not, in fact, an aircraft carrier, but a Helicarrier.

     Banner laughed nervously and shook his head, "Oh no, this is much worse."

     As the flight crew pulled oxygen masks over their faces and secured the remaining equipment, Natasha led us onto the equally active bridge.

     "Hover power check complete," an engineer said from his desk. "Position cyclic. Increase collective to eight percent."

     I glanced at Banner, who was carefully avoiding the gaze of the guards stationed at the entrance, and then turned to Steve, whose eyes were wide with wonder as he slowly moved across the expansive room.

     "Preparing for maximum performance takeoff," an agent announced. "Increase output to capacity."

     "Power plant performing at capacity," a second agent confirmed. "We are clear."

     "All engines operating. S.H.I.E.L.D. Emergency Protocol One-Nine-Three-Point-Six in effect," Agent Hill said before turning to Fury. "We are at level, sir."

     "Good. Let's vanish."

     Hill nodded, then instructed, "Engage retro-reflection panels."

     Standing behind an agent who had an exterior camera angle of the Helicarrier, I called, "Hey, Cap, come look at this."

     Steve moved to stand beside me, and our jaws dropped as the panels reflected the day's partially cloudy sky, effectively concealing the aircraft.

     "Reflection panels engaged," the agent in front of us said.

     Reaching into his pocket, Steve opened his wallet and retrieved a ten-dollar bill, which he wordlessly handed to Fury.

     Fury stared down at the bill for a moment, then smirked and turned to Banner, "Doctor, thank you for coming."

     "Thanks for asking nicely," Banner replied as they shook hands. "So, how long am I staying?"

     "Once we get our hands on the Tesseract, you're in the wind."

     "Where are you with that?"

     "We're sweeping every wirelessly accessible camera on the planet," Coulson answered. "Cell phones, laptops...If it's connected to a satellite, it's eyes and ears for us."

     Bent over one of the workstations and her gaze lingering on an agent's file, Natasha claimed, "That's still not gonna find them in time."

     "You have to narrow your field," Banner said. "How many spectrometers do you have access to?"

     "How many are there?" Fury countered.

     Shrugging out of his sports coat, Banner instructed, "Call every lab you know. Tell them to put the spectrometers on the roof and calibrate them for gamma rays. I'll rough out a tracking algorithm, basic cluster recognition. At least we could rule out a few places. Do you have somewhere for me to work?"

     Fury nodded and gestured to Natasha, "Agent Romanoff, could you show Dr. Banner to his laboratory, please?"

     Natasha smiled, "You're gonna love it, Doc. We got all the toys."

     As they left the bridge, I turned to Coulson with a sly smile, "So...my sister tells me you have a vintage collection of Captain America trading cards."

     Steve chuckled under his breath as the color drained from Coulson's face.

     "Yeah, she thought you might want me to sign them," he added, and I turned away to hide my smile.

     Clearing his throat, Coulson stuttered, "I...uh...well...I mean, if it's not too much trouble."

     Steve clapped Coulson on the shoulder, "No, no, it's fine."

     Coulson smiled, "It took me a couple of years to collect them all. Near mint. Slight foxing around the edges, but—"

     "We got a hit. A sixty-seven percent match," Agent Jasper Sitwell stated. "Wait. Cross match, seventy-nine percent."

     "Location?" Coulson inquired.

     "Stuttgart, Germany. Twenty-eight Königstrasse," Sitwell replied, enlarging the still shot he had captured of Loki. "He's not exactly hiding."

     The Norse God was tall, with jet black hair, pale skin, a narrow face, and mischievous eyes. Needless to say, he stood out in a crowd.

     "Captain," Fury called, causing me and Steve to turn in unison.

     "Captain Rogers," he clarified, and my cheeks flushed with embarrassment. "You're up."

     With a discreet sigh and a solemn nod, Steve turned on his heel and left the bridge, likely to don the suit Coulson helped design.

     "Agent Romanoff, I'll need you in the air with Natasha. Suit up."

     "Yes, sir."

     After slipping back into my jumpsuit and checking my assorted weaponry, I made my way to the hangar and dropped into the pilot's seat. As I prepared the Quinjet's systems for takeoff, I heard quiet footsteps behind me.

     "I think you're in my seat," Natasha said with a smirk.

     "Oh, right, sorry," I replied before moving to the co-pilot's chair. "All systems are ready for takeoff."

     "Still the perfectionist, I see."

     I chuckled, "Some things never change, I guess."

     A minute passed before I said, "I'm really happy fate reunited us, сестра, even if it took the possibility of a worldwide invasion to bring us together."

     Natasha smiled, "Well, I guess it's only fitting for us to reunite under these circumstances."

     Reaching over and giving my hand a squeeze, she said, "I missed you."

     Unable to meet her eyes without tearing up, I stared through the window and managed, "I missed you, too."

     "Do...do you have any idea where Yelena might be?" Natasha asked hesitantly.

     I shook my head, "I was hoping you knew."

     "I've tried searching for her, but I've never gotten a solid lead."

     I sighed, "Sounds about right."

     Clearing his throat behind us, Steve asked, "You ladies ready to go?"

     Swiveling in our seats, Natasha and I found Steve standing in the cargo hold, now dressed in an updated version of the iconic red, white, and blue suit he made famous during World War II.

     I whistled, "Wow, Cap, you clean up nice."

     Natasha laughed and whirled back toward the console as Steve's face turned the same shade of red as his shield. As the sky turned dark, Natasha eased the Quinjet out of the hangar and we set off for Stuttgart. As we neared the gala where Loki had last been spotted, we found the Norse God walking amongst a sea of people, whom he had seemingly corralled in the town square.

     "You were made to be ruled," Loki claimed. "In the end, you will always kneel."

     From the magical scepter in his hand to the extravagant armor and horned headpiece he wore, the God of Mischief's entire personality screamed narcissist.

     I had no patience for the type.

     "You ready to kick some ass, Cap?" I asked as I opened the main ramp.

     Lowering his helmet into place, Steve countered, "I prefer to avoid such language, Ma'am, but yes. Yes I am."

     As Steve turned to jump from the jet, an elderly gentleman stood in the crowd, the rest of whom were on their knees.

     "We will never kneel to men like you," the man claimed.

     Loki flashed an arrogant smile, "There are no men like me."

     "There are always men like you."

     The Norse God raised his scepter, "Look to your elder, people. Let him be an example."

     As the scepter started to glow, Steve leapt from the Quinjet and landed in front of the gentleman. With his shield raised, Steve deflected the energy mass produced by the scepter and knocked Loki off his feet.

     "You know, the last time I was in Germany, and saw a man standing above everybody else, we ended up disagreeing," Captain America said as he moved through the crowd.

     Loki only chuckled as he pushed to his feet, "The soldier. The man out of time."

     "I'm not the one who's out of time."

     Natasha laughed under her breath as she moved the Quinjet into position behind Steve, "You're in for a show, сестра."

     Arming the exterior Gatling gun located beneath the cockpit, Natasha aimed the weapon at the God of Mischief and ordered, "Loki, drop the weapon and stand down."

     Loki froze for a moment, then raised the scepter and fired at the Quinjet. Luckily, our reflexes had been honed to the peak of human ability in the Red Room, and Natasha tilted the aircraft out of harm's way as Steve moved to engage his otherworldly opponent. As my sister righted the Quinjet, I recalibrated the targeting system and took aim. Unfortunately, as both Rogers and Loki were fairly evenly matched, I was unable to find a clean shot.

     "This guy's all over the place," I muttered as he hurled Steve across the square.

     Suddenly, our communications system crackled and a man said, "Agent Romanoff. You miss me?"

     As AC/DC's "Back in Black" blasted from the Quinjet's PA system, I turned to Natasha, who only shook her head.

     "Don't ask."

     Leaning forward in my seat as a man-shaped object tore through the sky, I instantly recognized the red and gold armor made famous by Tony Stark's Iron Man. After all, his reputation preceded him. Aiming for Loki's chest, Stark fired the repulsors in the palm gauntlets of his suit and sent the Norse God flying backwards. The force of the blast tore the scepter from Loki's hand, and the Asgardian collided with a nearby staircase, knocking the air from his lungs.

     "Make your move, Reindeer Games," Stark quipped, revealing the many weapons in his heavily-armed suit.

     Looking between Stark and Rogers, Loki slowly raised his hands in surrender and revealed his armor to be nothing more than an illusion.

     "Good move."

     Without taking his eyes off the Norse God, Steve acknowledged, "Mr. Stark."

     "Captain."

     Once Loki had been secured and escorted onto the Quinjet, we began our return trip to the Helicarrier.

     Shortly after our departure, Fury's voice chirped in my ear, "Is he saying anything?"

     "Not a word."

     "Just get him here. We're low on time."

     "Copy that."

     Steve looked from Loki to Stark and frowned, "I don't like it."

     "What, Rock of Ages giving up so easily?"

     "I don't remember it being that easy. This guy packs a wallop."

     "Still, you're pretty spry for an older fellow. What's your thing, Pilates?"

     Steve's brow furrowed, "What?"

     "It's like calisthenics," Stark explained. "You might have missed a couple of things doing time as a Capsicle."

     I barely managed to cover my laughter with a cough as Steve's frown deepened.

     As Natasha smacked me on the shoulder to keep me from choking, Rogers replied, "Fury didn't tell me he was calling you in."

     "Yeah, there's a lot of things Fury doesn't tell you," Stark countered.

     My smile faltered at Stark's words, then vanished altogether when thunder rumbled overhead, despite the radar indicating that the skies were clear.

     "Where's this coming from?" Natasha muttered to herself.

     When lightning flashed across the sky, Loki's shoulders hunched and he flinched in his chair.

     "What's the matter?" Steve asked. "Are you scared of a little lightning?"

     "I'm not overly fond of what follows," the Asgardian answered.

     Squinting against the blinding light of the bolts that tore jagged holes in the night sky, Natasha and I struggled to keep the Quinjet steady as the storm rapidly grew in size and intensity. When the Quinjet violently shuttered and rocked from side-to-side, I checked each of the flight systems for damage, fearing we had been struck by lightning. Even as the reports indicated that the aircraft was unharmed, Stark was opening the rear hatch and sliding his mask into place.

     "What are you doing?" Steve asked.

     Before Stark could answer, an individual who – based on the case files we had been given – could only be Loki's brother, Thor, landed on the ramp. When Stark raised his gauntlets to fire, the Norse God of Thunder swung his hammer and sent Tony flying into the back of my seat. I jolted forward in my seat and just managed to avoid slamming against the dashboard as Thor grabbed Loki by his tunic and leapt from the jet.

     Stark groaned as he got to his feet, "And now there's that guy."

     "Another Asgardian?" Natasha asked.

     "Loki's brother!" I shouted over the wind.

     "That guy's a friendly?" Steve replied, bewildered.

     "Doesn't matter," Stark stated as he marched toward the open hatch. "If he frees Loki or kills him, the Tesseract's lost."

     "Stark, we need a plan of attack!" Steve said.

     "I have a plan. Attack."

     Steve sighed as Stark flew after the Asgardians, then reluctantly grabbed one of the standard-issue parachutes.

     "I'd sit this one out, Cap," I warned.

     "I don't see how I can."

     "These guys come from legend. They're basically gods."

     "There's only one God, Miss. And I'm pretty sure He doesn't dress like that."

     Before I could argue, he hooked his shield around his arm and jumped from the Quinjet with nothing more than government-grade fabric strapped to his back.

     Shaking my head, I turned to Natasha, "I'd ask if they ever listen, but I'm starting to think I know the answer."

     My sister smirked, "Yeah, I would get used to it."

     Circling above the dense forest, we attempted to locate the wayward Avengers by following the flashes of light that emanated from the forest floor. After several minutes, a concussive blast rocked the forest and leveled every pine tree within a one-mile radius. Natasha and I locked eyes, then guided the Quinjet toward the manmade clearing and hovered above the three adversaries, all of whom were now splayed across the ground.

     As the trio staggered to their feet, I opened the PA system and asked, "Are we done, here?"

     The Asgardian looked from his opponents, then met our eyes through the windshield and nodded. After detaining Loki aboard the aircraft once more, we completed the second half of our flight and finally returned to the Helicarrier. By the time we landed in the hangar, a battalion of heavily-armed S.H.I.E.L.D. agents were waiting to escort Loki to his specially-made cell. Gesturing for me and Natasha to follow, Fury led us to the private room where Loki was being held and stopped just short of the threshold.

     When Natasha arched an eyebrow, Fury answered her silent question in a low voice, "You both have the best training when it comes to threat assessment. Tell me what you see."

     Without another word, Fury turned on his heel and marched into the room. Natasha and I followed close behind, then positioned ourselves on either side of the director.

     Moving to a nearby console that controlled the pressurized cell, Fury began, "In case it's unclear, if you try to escape, if you so much as scratch that glass, it's thirty thousand feet straight down in a steel trap."

     I planted my feet against the metal walkway as Fury opened a large hatch located directly beneath Loki's cell, causing the wind to whip around the cavernous room.

     "You get how that works?" Fury asked as Loki took several steps forward and peered over the edge. "Ant, boot."

     The God of Mischief chuckled, "It's an impressive cage. Not built, I think, for me."

     "Built for something a lot stronger than you."

     I glanced in Natasha's direction to find she wore the same troubled expression.

     "Oh, I've heard," Loki replied before looking directly into the nearest camera. "A mindless beast. Makes play he's still a man. How desperate are you, that you call on such lost creatures to defend you?"

     "How desperate am I?" Fury repeated, moving closer to the cell. "You threaten my world with war. You steal a force you can't hope to control. You talk about peace, and you kill because it's fun. You have made me very desperate. You might not be glad that you did."

     "Oh, it burns you to have come so close. To have the Tesseract, to have power, unlimited power. And for what? A warm light for all mankind to share. And then to be reminded of what real power is."

     The Asgardian's icy gaze swept across the room, and though his eyes met mine for only a moment, that quick glimpse into his fractured mind caused me to shiver.

     Fury scoffed, "Well, let me know if 'real power' wants a magazine or something."

     We made our way back into the hall before Fury closed the door and turned to face us. He held my gaze for a moment, then Natasha's.

     Satisfied with whatever he saw in our eyes, he nodded and said, "Good. We're on the same page."

     As he walked away, I muttered, "I don't like this."

     "Me neither," Natasha agreed, and my heart sank into my stomach.

     It was never a good sign when two graduates of the Red Room were worried about events to come, especially when they had been held to a higher standard during their time under Drekyov's control. After all, Natasha and I had both been tasked with carrying out high-stake assassinations, which meant we also knew what was at risk if we failed.